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From: Heiner Kallweit <hkallweit1@gmail.com>
To: Sven Van Asbroeck <thesven73@gmail.com>
Cc: Bryan Whitehead <bryan.whitehead@microchip.com>,
	Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>,
	David S Miller <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Andrew Lunn <andrew@lunn.ch>,
	netdev <netdev@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH net v2] lan743x: fix rx_napi_poll/interrupt ping-pong
Date: Fri, 11 Dec 2020 13:50:12 +0100	[thread overview]
Message-ID: <f462a419-aa6f-38f7-573e-c48c2a859f55@gmail.com> (raw)
In-Reply-To: <CAGngYiXsyRH=5UYwaCkVDDGkRX6m_Cw9iam+nSRZwA1=ZNPnOQ@mail.gmail.com>

Am 11.12.2020 um 13:43 schrieb Sven Van Asbroeck:
> Hi Heiner,
> 
> On Thu, Dec 10, 2020 at 2:32 AM Heiner Kallweit <hkallweit1@gmail.com> wrote:
>>
>>
>> In addition you could play with sysfs attributes
>> /sys/class/net/<if>/gro_flush_timeout
>> /sys/class/net/<if>/napi_defer_hard_irqs
> 
> Interesting, I will look into that.
> 
I run a 1Gbit chip with gro_flush_timeout = 20000 and napi_defer_hard_irqs = 1.
This helped to reduce interrupt load significantly under iperf3
(w/o interrupt coalescing at chip level)

>>> @@ -2407,7 +2409,7 @@ static int lan743x_rx_open(struct lan743x_rx *rx)
>>>
>>>       netif_napi_add(adapter->netdev,
>>>                      &rx->napi, lan743x_rx_napi_poll,
>>> -                    rx->ring_size - 1);
>>> +                    64);
>>
>> This value isn't completely arbitrary.
>> Better use constant NAPI_POLL_WEIGHT.
>>
> 
> Thank you, I will change it in the next patch version.
> 


      reply	other threads:[~2020-12-11 12:51 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-10  3:55 [PATCH net v2] lan743x: fix rx_napi_poll/interrupt ping-pong Sven Van Asbroeck
2020-12-10  7:32 ` Heiner Kallweit
2020-12-11 12:43   ` Sven Van Asbroeck
2020-12-11 12:50     ` Heiner Kallweit [this message]

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